Sort ArrayList Elements in Descending Order Java

In this article, we will see how to sort ArrayList elements in descending order using sort(List list, Collections.reverseOrder()) method.

Examples:
Input:    23, 54, 32, 56, 78, 65
Output: 78, 65, 56, 54, 32, 23

Input:    Microsoft, Vmware, Salesforce, Apple, Facebook
Output: Vmware, Salesforce, Microsoft, Facebook, Apple

Example 1:

The below programs shows how to use sort(List list,Collections.reverseOrder()) to sort ArrayList elements in descending order. Here the elements are of Integer type.

import java.util.ArrayList;
import java.util.Collections;

public class ArrayListSortDescendingExample {

	public static void main(String[] args) {
		ArrayList<Integer> numbers = new ArrayList<>();
		numbers.add(23);
		numbers.add(54);
		numbers.add(32);
		numbers.add(56);
		numbers.add(78);
		numbers.add(65);

		System.out.println("Elements before sorting : " + numbers);
		Collections.sort(numbers, Collections.reverseOrder());
		System.out.println("After sorting in descending order : " + numbers);

	}
}

Output:

Elements before sorting : [23, 54, 32, 56, 78, 65]
After sorting in descending order : [78, 65, 56, 54, 32, 23]

Example 2:

Let’s look at the program.

import java.util.ArrayList;
import java.util.Collections;

public class ArrayListSortDescendingDemo {

	public static void main(String[] args) {
		ArrayList<String> companies = new ArrayList<>();
		companies.add("Microsoft");
		companies.add("Vmware");
		companies.add("Salesforce");
		companies.add("Apple");
		companies.add("Facebook");

		System.out.println("Companies before sorting : " + companies);
		Collections.sort(companies, Collections.reverseOrder());
		System.out.println("ArrayList Elements after sorting in descending order : " + companies);
	}
}

Output:

Companies before sorting : [Microsoft, Vmware, Salesforce, Apple, Facebook]
ArrayList Elements after sorting in descending order : [Vmware, Salesforce, Microsoft, Facebook, Apple]

In this article, we saw how to use Collections.reverseOrder().

Further Reading:

ArrayList Reference.